This invention relates to optical discs that include multiple data layers and are configured to receive analytes which can be detected by an optical disc reader.
Optical discs have been used for detection and characterization of biological and chemical samples. For instance, see WO 96/09548 (Gordon), EP A 392475 (Idemitsu), EP A 417 305 (Idemitsu), EP A 504432 (Idemitsu), and WO 98/12559 (Demers), all of which are incorporated herein by reference. Other examples of using optical discs to detect investigational samples can be found in U.S. Provisional Application No. 60/252,725, entitled xe2x80x9cOptical Bio-Disc Including Microfluidic Circuit for Separation and Quantification of Agglutinated Microparticles or Cells and Methods Relating Theretoxe2x80x9d, U.S. Provisional Application No. 60/252,726, entitled xe2x80x9cBioactive Solid Phase for Specific Cell Capture and Optical Bio-Disc Including Samexe2x80x9d, and U.S. Provisional Application No. 60/257,705, entitled xe2x80x9cSurface Assembly for Immobilizing DNA Capture Probes and Bead-Based Assay Including Optical Bio-Discs and Methods Relating Theretoxe2x80x9d all of which are incorporated herein by reference.
Some of these previously described optical discs, however, are not designed to be read by standard optical disc readers, such as standard CD or DVD readers. For instance, the optical discs disclosed in EP A 392 475 (Idemitsu), EP A 417 305 (Idemitsu) and EP A 504 432 (Idemitsu) are not designed to be read by standard CD or DVD disc readers. The discs described in WO 96/09548 (Gordon) require the use of two optical detectors, one to detect the tracking information and the other to detect surface structures. In contrast, reading a standard CD or DVD needs only one optical detector.
Therefore, there is a need to design and manufacture an optical disc configured to receive an investigational sample that can be detected by a standard optical disc reader or an optical disc reader modified therefrom.
Over the past decade, scanning laser microscopy (SLM) has revolutionized life science imaging. However, SLM demands expensive and specialized optical equipment. Consequently, there exists a need to provide an inexpensive, generic device which can carry out laser scanning over microscopic specimens.
The present invention discovers that the minimum mechanical requirements for SLM, i.e. laser, focusing and detection optics, precision scanning means, and computer interface, may all be provided by a standard optical disc reader or an optical disc reader modified therefrom. Therefore, it is desirable to create an optical disc that can hold a microscopic sample that can be scanned by a standard optical disc reader. Such an optical disc presents a marked advantage over existing SLM technologies.
In order for a standard optical disc reader to operate an optical disc, the optical disc reader is typically required to be able to (1) accurately focus above the operational surface of the optical disc, (2) accurately follow the spiral track or utilize some form of uniform radial movement across the optical disc surface, (3) recover enough information to facilitate a form of speed control, such as CAV, CLV, CBR, or ZCLV, (4) maintain proper power control by logical information gathered from the optical disc or by signal patterns detected in the operational surface of the optical disc, and (5) respond to logic information that is used to control, for example, the position of the objective assembly, the speed of rotation, or the focusing position of the laser beam.
A typical optical disc system uses elements of the optical medium itself to satisfy at least some of these operational requirements. For instance, in a typical CD, the disc substrate is impressed with a spiral track made up of a series of embossed or impressed pits and lands. Light reflected from these pits and lands can be used to generate signals. These signals are used by the optical disc reader to maintain proper focusing and tracking. In a CD-R disc, a wobble groove is used to generate operational signals during disc recording. Dye marks are created during disc recording, and these dye marks may provide the requisite tracking structures during subsequent reading. Generally, under each of conventional optical disc standards, the structures that encode data may simultaneously serve to provide operational signals that enable an optical disc reader to operate the optical disc.
Conventional optical disc standards make no provision with respect to acquisition of information from investigational features, such as biological, chemical, or biochemical specimens, that are disposed on the disc. Investigational features disposed on the disc may disrupt the tracking of the disc. In addition, investigational structures or features may be sufficiently separated from operational structures, therefore preventing an optical disc reader from tracking the disc and detecting the investigational features concurrently and discriminably.
Therefore, there is a need to provide an optical disc that allows an optical disc reader to detect the investigational features without disrupting the tracking of the disc. There also exists a need to provide an optical disc that allows an optical disc reader to track the disc and read the investigational features concurrently and discriminably.
Therefore, it is an object of this invention to provide an optical disc configured to receive an analyte of interest that can be detected by an optical disc reader.
In accordance with one aspect of this invention, the optical disc includes (1) a first layer including optically readable structures which have encoded tracking information, and speed information enabling an optical disc reader to rotate the optical disc at a speed that is determinable from the speed information; (2) a second layer including optically readable structures; and (3) an analyte section capable of receiving an analyte which can be read by the optical disc reader. The analyte section may include a first chamber, and at least part of the first chamber is within the optical disc. The optical disc may also include a channel which is located in at least one of the first layer and the second layer and which connects to the first chamber. The optical disc reader may be a DVD reader or a CD reader.
In one embodiment, the channel includes a valve that can be regulated by optically readable data encoded in the optical disc.
In another embodiment, the analyte section includes a second chamber, and at least part of the second chamber is within the optical disc. The optical disc may also include a channel which is located in at least one of the first layer and the second layer and which connects to the second chamber.
In accordance with another aspect of this invention, the optically readable structures in the first layer are impressed in a surface of the first layer and are coated with a first reflective layer, whereas the optically readable structures in the second layer are impressed in a surface of the second layer and are coated with a second reflective layer. The first reflective layer and the second reflective layer are located between the first layer and the second layer.
In one embodiment, at least one of the first and second reflective layers is semi-reflective.
In another embodiment, the first chamber includes a sample surface that is located within 15 micrometers from either the first data surface or the second data surface. The sample surface of the first chamber may hold the analyte.
In yet another embedment, at least one of the first data surface and the second data surface includes a cut-away area or window that lacks optical readable structures that have encoded tracking information. A surface of the first chamber may include the cut-away area or window. The cut-away area or window may lack reflective coatings.
In a preferred embodiment, the optically readable structures in the first layer or the optically readable structures in the second layer have encoded assay information for conducting an assay on the analyte.
In another preferred embodiment, the optically readable structures in the first layer or the optically readable structures in the second layer have encoded focus control information enabling the optical disc reader to move the focal point of a reading beam in a manner determinable from the focus control information.
In accordance with yet another aspect of this invention, at least one of the first layer and the second layer is a hologram. Preferably, at least part of an image plane of the hologram is located with the analyte section. The analyte section may include a surface that is located within 15 micrometers from the image plane of the hologram. The surface can hold the analyte. In one embodiment, the surface is within the image plane of the hologram.
In accordance with another aspect of this invention, a method is provided for the detection of the analyte held in the analyte section of the optical disc. The method includes: (1) providing the optical disc to the optical disc reader; (2) reading the optical disc; and (3) obtaining at least one signal which is indicative of the presence of the analyte.
In one embodiment, the optical disc reader includes at least two detectors, one detector being capable of generating tracking signals, and the other detector being capable of receiving radiation that passes through the optical disc and generating the signal which is indicative of the presence of the analyte.